It is common to provide storage units which are movable by power into contact with one another and can be selectively separated to form an access space. The units may be any device arranged in linear, circular, horizontal, vertical, or any other fashion where sequential order is maintained. The units may be file cabinets, trays, lockers, carriages, platforms, book storage units, freezer lockers, refrigerated units, furniture storage units, tape storage units, or any other device intended for storing, filing, preserving, protecting, accumulating and the like.
The purpose of maintaining contact proximity is to reduce the amount of area, distance, floor space or other volume required for storage. The purpose of selecting a space between any two of the storage units is to gain access to a desired storage location.
While the concept of controlling storage units as described above is not new, and numerous methods have been employed in the past, the present invention is directed to a control system which uses standard control functions in each unit, without the necessity for central control, computing, or monitoring, thus saving in control hardware, and eliminating the need for different assemblies at different locations. The control system can be designed with a standard control device for each of the units, including those which are placed at the end of the sequence. This reduces different replacement control devices to one type with concimitant savings in stock cost and control and simpler maintenance techniques and routines.
In addition, the control system provides for safety controls that require the operator to perform reset functions before operation thereof; wherein once reset, the system must be operated during a predetermined period of time; wherein if operation is discontinued, the operator must perform a reset function; wherein the controls for operation are oriented the same on each storage unit; and wherein there is a redundant safety system deactivating the solid state logic as well as the mechanical relay control.